We argue that query expansion (QE) based on the full ses- sion improves the overall search experience provided that we know how to adapt the QE weighting schema to a user's search proficiency. We propose a strategy to predict search ability from session parameters. Us- ing an exponential model and these metrics we set user dependent QE coefficients. We evaluate this approach on TREC 2011 session track data.
B. Carterette , E. Kanoulas , P. Clough , M. Sanderson
Information Retrieval over Query Sessions
Human-Centered Data Analytics

Boscarino, C., Hollink, V., & de Vries, A. (2012). Adapting Query Expansion to Search Proficiency. In B. Carterette, E. Kanoulas, P. Clough, & M. Sanderson (Eds.), Proceedings of ECIR workshop 2012. ECIR LNCS.